Abstract Circular dichroism (CD) spectroscopy of secondary structure conformation of the purified green bell pepper hydroperoxide lyase (HPL), cloned in the yeast Yarrowia lipolytica, was investigated. The CD spectra of HPL in iso-octane, obtained at 60 °C, in the presence of the reducing agent dithiothreitol showed dramatic increase in α-helix content. The enzyme conformation remained unchanged over a range of pH values of 5.0–7.0. Using 13-hydroperoxide of linoleic acid (13-HPOD) as substrate, the biocatalysis of HPL in organic solvent media, including chloroform, dichloromethane, hexane, iso-octane, octane and toluene, was investigated. The results indicated an increase in HPL activity in the biphasic hexane medium.